A few years ago, Mark Steyn sagely observed, “In America today, few activities are as profitable as a ‘nonprofit.’” Nothing warrants changing that assessment now. President-elect Trump has a lot on his plate if he plans to turn around the ship of state. But if it’s not too presumptuous, I’d like to add one more item to his agenda: a substantial rewrite of the laws respecting our tax-exempt sector, reining in private foundations.